Design of a metallic Ising spin glass in the ${\mathrm{Y}}_{1-x}{\mathrm{Tb}}_x{\mathrm{Ni}}_2{\mathrm{Ge}}_2$ system

There has been much interest in the past ten years in the effects of applying a transverse magnetic field on the freezing temperature of Ising spin glasses. The focus of this study is to search for and characterize a metallic Ising spin-glass system. This is accomplished by site diluting yttrium for terbium in the crystalline material ${\mathrm{TbNi}}_2{\mathrm{Ge}}_2.$ Pure ${\mathrm{TbNi}}_2{\mathrm{Ge}}_2$ is an Ising antiferromagnet with several distinct magnetic states below 17 K. As the terbium is diluted with yttrium, magnetic coupling and ordering temperatures are suppressed in a monotonic way, as is seen in measurements of the transition temperatures and analysis of the high-temperature Curie-Weiss behavior. At low concentrations of terbium, below $x\sim 0.35,$ long-range order is no longer detected and a spin-glass-like state emerges. This state is studied through a variety of measurements: dc and ac susceptibility, resistivity, and specific heat. These data are then compared to that of other well characterized spin-glass systems. It is concluded that there is a region of concentrations for which an Ising spin-glass state is formed with the best spin glasses existing for $x<~\mathrm{0.30.}$